ubuntu命令无法使用

你当初改了什麼，就改回去啊！

你把$PATH改没了,它能找到命令才怪......

$sudo gedit ~/.profile。打开，一般如下：
# ~/.profile: executed by the command interpreter for login shells.
# This file is not read by bash(1), if ~/.bash_profile or ~/.bash_login
# exists.
# see /usr/share/doc/bash/examples/startup-files for examples.
# the files are located in the bash-doc package.
# the default umask is set in /etc/profile; for setting the umask
# for ssh logins, install and configure the libpam-umask package.
#umask 022
# if running bash
if [ -n "$BASH_VERSION" ]; then
# include .bashrc if it exists
if [ -f "$HOME/.bashrc" ]; then
. "$HOME/.bashrc"
fi
fi
# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
PATH="$HOME/bin:$PATH"
fi
哦，不用设置了嘛。你看看你的这个文件PATH="$HOME/bin:$PATH"这行是不是这样，是不是少了$HOME/bin:。如果没少，那你把/usr/bin软链接到~/bin目录下看看。